Mechanical Roller Lifters
Thanks Andy. Hughes and Howard both have spec me a cam and springs and lifters. Like i said. I really did not have to even ask the question. There is good and there is cheap. So you will no i can have all my ducks in a roll and not know if i am going with Hughes or Howard Cams. You assumed a lot in your answer. All though your point is well taken. But i do have all the info you assumed i didn't have. But i ask a dumb question i should expect and answer like yours.
Heres my rule. I never violate it because every time I do it bites me.
Never buy a lifter with a wheel diameter less that .800 and .810 is better.
The cheap lifters with the .750 wheel are just not good enough when the base circle gets bigger.
If you think about it, when the core gets bigger (stiffer core and bigger is always better) that means the base circle can be bigger. Chrysler uses bigger cores than GM. So the .750 wheel is ok for that junk. Most of those guys are using .904 bodied/.810 wheel lifters in their Chevy stuff anyway.
So let's say you have a SBC sized core and a SBM core (I'm most familiar with those numbers but the BBC/BBM is the same difference) and both cores have a .400 lobe. The cam with the bigger bearings and bigger core will have a bigger base circle. So when it's all fleshed out, even though the net lift at the lifter is .400 off the base circle, the Chrysler roller wheel had to travel farther to complete one lift cycle than the Chevy. That means the wheel on the Chrysler lifter had to spin faster (more RPM) to achieve the same lift as a Chevy.
What that all means is that .750 wheel is speed limited. So RPM and base circle size affect roller speed. You'll find the limit of the .750 wheel with a Chrysler long before you will a Chevy. They literally turn into a tuning fork and vibrate themselves to death.
That's why I always say spend the money for the bigger wheel.
Crane Pro Series are great lifters. BAM are very nice. Crower is making some really nice stuff and one of the guys at Crower is here on FABO. I forget his name.
Isky has some cool stuff too.
